George benjamin poindesteb



G. B. POINDEXTER.

BURGLAR ALARM FOR MOTOR VEHICLES.

APPLICATION FILED FEB. 20. 1919. 1,818,299.

Patented Oct. 7,1919 3 ,9 35 I2 I il 25 O 32 I H!- J 20 l J 23 8 7 3/ a6 as 22 /5 I ewya in rrr ran BURGLAB-ALARM FOR MOTOR-VEHICLES.

3 3 299 Specification of Letters Patent. Patented Got, '7, @919.

Application filed February 20, 1919. Serial No. 278,297.

To all whom it may concern: of spring metal and are provided with con- Be it known that I, GEORGE BENJAMIN tact members 14 and 15 respectively that are Pornnnxrnn, a citizen of the United States, adapted to be bridged by a contact bar or residing at Seattle, in the county of King and switch blade 16 that is carried by the'arm State of Washington, have invented a cer- 8, the sides of the contact members 14 and tain new and useful Improvement in Bur- 15 that are first engaged by the arm 8 being glar-Alarms for Motor-Vehicles, of which inclined or beveled so that the contact bar 16 the following is a specification. will ride over them more easily when the My invention relates to improvements in arm is turned from an upright position burglar alarms for automobiles and the into the position shown in Figs. 1 and 2. object of my invention is to provide a lock- 17 is a plunger having an inclined or bevcontrolled alarm of relatively cheap and eled outer end that is adapted to project simple construction that may be easily inwithin a hole 18 in the contact bar 16 the stalled on an automobile-in connection with plunger 17 being guided and en ported for the ignition system so that when the auto endwise movement within suita le holes in mobile is left standing in a public place the the spring 12 and fiber plate 11 and being alarm may be set in such a position that it urged outwardly by a relatively light comwill be automatically sounded if current is pression spring 20 that is arranged to press caused to flow through the conductors that against a collar 21 on the plunger. lead to the spark plugs in an attempt to start Secured to the rear side of the fiber plate the automobile. 11 is a two part socket 22 that fits over a ball I accomplish this object by devices illus- 23 on the end of a shank 24. The outer end trated in the accompanying drawings, of the shank 2 1 is externally threaded and wherein-- is adapted to screw within the internally Figure 1 is a view partly in section'and threaded inner end of a lock socket 25. The partly in elevation of an alarm constructed lock socket 25 projects outwardly through inaccordance with my invention; and and is somewhat loosely secured to the side Fig. 2 is a plan view of the same with of the box 5 and the end ofsuch socket is the cover removed. 1 provided with an inserted rotatable member Referring to the drawings throughout 26 having a peculiarly shaped key hole which like reference numerals indicate like wherein a key'27 may be inserted. parts, the numeral 5 designates a rectangu- The threaded end of the shank 24 has a lar metallic box, the walls of which are prolongitudinally extending keyway 28 that 15 vided with relatively small perforations that suitably ridged and channeled for the receppermit sound to escape from the box 5 and tion of the key 27 and the end of suchshank such box being of strong and solid construcis provided with one removable section 30 tion so that it will be difficult to gain access that is secured by screws 31 to the mam part thereto. of the shank and that may be removed and The box 5 is secured to the car and arreplaced by a section that is ridged and ranged so that the spark control rod 7 that channeled in a different manner and which extends-from the steering wheel downwardly will require a different key to operate. along or through the steering post may pass The fiber plate may be tilted to the left therethrough and the spark control rod 7 is from the position shown in F 1g. 1 by 111- provided within the box 5 with a fixedly sertingthe key 27 and screwmg the shank 24:

' mounted arm 8 preferably of fiber that prointo the socket 25 thereby moving the conjects at right angles therefrom and turns 'tacts 14: and 15 away from the arm 8 so that with the rod when the latter is oscillated the arm Smay oscillate freely withouttouchto control the spark. ing such contacts Pivoted to the bottom of the box 5 by a The spring 12 18 connected by an electric hinge 10 is a plate preferably of fiber or circuit wire 32 with a circuit wire 33 that other suitable insulating material that proleads from a source of supply of current, jects upwardly at one side of the spark conas from a storage battery and the spring trol rod 7 and has two U-shaped contact 13 may be connected by an electric circu t carriers 12 and 13 secured thereto in inwire 34 with one terminal of an electric 11o sulated relation with respect to each other. bell 36, the other terminal of the bell 36 The contact carriers are preferably formed being grounded so that when the circuit is closed by bridging the terminals 14 and 15 current willflow through the bell and cause it to ring.

In operation when the devlce is installed as hereinbefore described with the fiber plate 11 in the position shown in Figs. 1 and 2 and the spark retarded, the contact arm 8 will be turned into a substantially upright position thereby opening the switch formed by the contact members 14 and 15, but when the spark is advanced to start the engine the contact arm 8 will be turned downwardly into a substantially horizontal position thereby bridging the contact terminals 14 and 15 and causing the bell 36 to ring.

When the automobile is in use the driver will insert the key 27-into the lock and by turning the shank 24 will tilt the fiber plate 11 to the left as viewed in Fig. 1 until the contact members 14 and 15 are withdrawn. a suflicient distance to be clear of the path of movement of the contact bar 16 when the latter is moved by oscillation of the spark control rod 7 thus making it possible to oscillate the rod 7 at will without closing the circuit to the bell 36.

When the automobile is to be left standing in a location Where there is danger of its being stolen the driver will insert the key 27 and by turning the shank 24 will move the fiber plate 11 into sucha position that the contact members 14 and 15 are in the path of movement of the contact bar 16 and will be bridged by such bar when the spark control rod 7 is rotated thereby closing the circuit and ringing the bell 36.

When the contact bar 16 is moved into the position shown in the drawings to close the circuit the plunger 17 will enter the recess 18 and lock the bar in such position thus preventing the circuit from being again broken until the plate 11 is moved away from the arm 8 by turning the shank 24.

The lock socket 23 is secured in the side of the casing 5 in such manner that it will not rotate but is free to move or tilt slightly to compensate for the tilting movement of the fiber plate 11.

WVhile I have described this alarm mechanism as connected with the spark control rod of an automobile it will be understood that the same will operate when connected fvith any shaft or similar member that oscilates;

Obviously changes in the precise form of construction and arrangement of parts of my invention may 'be made without departing from the spirit thereof.

What I claim is:

1. Burglar alarm for motor vehicles com prising a casing, a shaft arranged to project into said casing, a plate hinged to one side of said casing,- switch terminals carried on said plate in insulated relation with respect to each other, an arm secured to said .connecting one end of said shank shaft, a switch bar on said arm arranged to bridge said terminals, means for movlng said plate away from said arm to move said terminals out of the path of said switch bar, an electric bell, and an electric circuit connecting with said bell and arranged to be closed when said contact bar bridges said terminals.

2. Burglar alarm for motor vehicles comprising a casing, a shaft mounted for 05011- lation and arranged to project into said casing, a plate hinged to one side of said casing, switch terminals carried on sald plate in insulated relation with respect to each other, an arm secured to said shaft, a switch bar on said arm arranged to bridge said terminals, means for locking said switch bar in engagement with said terminals, key operated means for moving said plate away from said arm to move said terminals out of the path of said switch bar, an electric bell and an electric circuit connecting with said bell and arranged to be closed to ring said bell when said contact bar bridges said terminals.

3. Burglar alarm for motor vehicles comprising a casing, a shaft arranged to project into said casing, a support hinged to the side of said casing, two terminals carried by said support in insulated relation with respect to each other, an arm secured to said shaft, a contact bar on said arm and arranged to make electrical contact between said terminals when said shaft is oscillated, a lock provided'in one side of said casing, a shank adaptedto ranged to fit said lock and turn said shank, a universal joint connecting said shank with said upright support whereby said support may be moved toward'and away from said contact bar by turning said shank, an elec tric bell, and an electrical circuit connected with said bell and arranged to be closed wlien said contact bar engages said termina s.

4. A burglar alarm for motor vehicles comprising a casing, a shaft adapted to project into said casing, a support hinged to one side of said casing, two U-shaped spring members secured to said support and insulated from each other, switch terminals on said spring members, an electric bell, an electric circuit connected with said bell through said switch terminals, an arm secured to said shaft, a switch bar on said arm and arranged to close the contact between said terminals, a lock member accessible from the exterior of said casing said lock member havin an internally threaded socket, an externa ly threaded shank arranged to screw into said .socket, a key adapted to be inserted in said lock member to turn said shank and a universal joint with said upright support whereby said support may screw into said look, a key arbe moved toward and away from said contact bar.

5. The combination with the spark control shaft of a motor vehicle, of a casing arranged to have said spark control shaft project therethrough, a plate hinged to one side of said casing, two U-shaped spring members secured to said plate and insulated from each other, switch terminals on said spring members, a contact arm on said spark control shaft, a switch blade on said contact arm and arranged to connect said switch terminals when said shaft is oscillated said switch blade having a recess therein, spring detent means arranged to enter said recess and lock said switch blade in engagement with said terminals, a lock member accessible from the exterior of said casing said lock member having an internally threaded socket, an externally threaded shank arranged to screw into said lock member said shank being provided with a longitudinally extending keyway, a key adapted to be inserted into said lock and into the keyway in said shank to turn said shank, a universal joint connecting one end of said shank with said hinged plate, an electric bell disposed within said casing, a circuit wire connecting one of said spring members with a source of electricity, and another circuit wire connecting said other spring member with one terminal of said electric bell the other terminalof said bell being grounded.

In witness whereof, I hereunto subscribe my name this 11th day of February, A. D. 1919.

GEORGE BENJAMIN POINDEXTE-R. 

